The correct answer is letter D. <span>When a sound wave strikes your eardrum, it causes forced vibrations that are transferred to the bones in the middle ear. As this phenomena occurs, signals are sent to the brain and the brain analyzes the sound and converts it into an understandable signal. </span>
Natural selection is based on Darwin’s observation that individuals most likely to survive and reproduce are those with traits best suited to their current environment.
The oesophagus is the region of the alimentary canal where the food passes without the absorption of nutrients. In oesophagus, we find peristalticmovement which is basically rhythmic contraction and relaxation of the oesophagus in order to facilitate the easy passage for the food to pass from mouth to stomach.
The oesophagus is a muscular tube which measures about 8 inches long.
